#box1{
    width:100px;
    height: 100px;
    background-image: url(./dahuaxiyou.jpg);
    background-repeat: no-repeat;
    background-size: 100% 100%;
}

#box2{
    width:200px;
    height: 200px;
    background-image: url(./xiaociwei.jpg);
    background-repeat: no-repeat;
    background-size: 100% 100%;
}